Storage Optimizer

One building instead of unloader + belt + loader. Storage Optimizer moves whole stacks from one chest
or warehouse straight into another – up to 20 stacks at once, no belts, no inserters, and built from the
ground up to be gentle on UPS.

before:  [chest] → unloader → belt → loader → [chest]
now:     [chest] → Storage Optimizer → [chest]

A transfer is stack size × stacks per transfer – e.g. iron plates 100 × 5 = 500 plates at once.

Features

• Whole-stack transfers – one transfer per cycle, and only when the source holds all items and the
  target has room for all of them ("all or nothing"). No half stacks left behind.
• Several stacks at once – 1–20 stacks per transfer (limit configurable); bigger transfers are cheaper
  per item. Can also be driven by any circuit signal you choose ("Stacks per
  transfer from circuit" in the panel – like the native "Set stack size").
• No belts needed – place it between two chests, warehouses or machines, press R to reverse the direction.
• Assembling machines and furnaces – as a target it fills the machine's input (e.g. a one-off buffer of
  "iron plates × 2 stacks"), as a source it takes the finished products. Fuel is left to inserters.
• Tiers from any belt mod – every belt in the game (vanilla, Space Age, or any belt mod) automatically
  gets its own tier with a matching speed, recipe and technology. Yellow tier: one transfer per second,
  faster belts are proportionally faster.
• Custom stack size – Auto (the item's stack) or any amount, e.g. 5000. Not limited to 255.
• Filters and circuit control – 5 filters with whitelist/blacklist and quality comparison;
  enable/disable by condition, stack size and stack count from signals, filters from signals.
  Wires connect to a terminal on the building's gearbox.
• Blueprint support – stack size and stack count survive blueprints, copy-paste and tier upgrades.
• Quality, spoilage and item data are preserved.
• UPS-friendly – the building is never updated by the engine; the script touches it only once per
  transfer interval. Benchmark: see below.
• Cheap on power – 20 kJ per transfer + 5 kJ for each additional stack (e.g. 500 plates for 40 kJ);
  an idle building uses no power, and a small energy reserve keeps power spikes low.
• Hand-made look – weathered industrial graphics rendered in Blender, arrows coloured by tier.

How to use

1. Research the belt of the tier you want (the first tier comes with Fast inserter).
2. Place the Storage Optimizer between two chests. It takes from the chest behind it (the gearbox side)
   and puts into the chest in front of it (where the arrows point).
3. Open it to set filters and circuit conditions (native inserter window), stack size and stacks per
   transfer (panel on the right).

Compatibility

• Factorio 2.0, with or without Space Age.
• Overhaul mods: each tier has its own technology whose prerequisites are derived from the belt and from every
  recipe ingredient, so the tier is never unlocked before its ingredients – also in reshuffled tech trees.
  Tested with Pyanodon and Bob's mods. Ingredients are intermediates (circuits, inserters, belts), so
  overhaul mods make the recipe more expensive on their own; missing items fall back to simpler ones.
• Works with any mod that adds belts (tiers are generated automatically), any mod that adds chests or
  warehouses of type container / logistic-container and any mod that adds assembling machines or furnaces.
• Default control signals are the plain letters S (stack size) and N (stacks per transfer);
  any other signal can be chosen.

Known limitations

• Works with chests, warehouses, assembling machines and furnaces – not with wagons, rocket silos or labs.
• Fuel is not handled (use an inserter for fuel).
• The native inserter window shows the Override stack size slider – it is ignored. Stack size and
  stacks per transfer are set in the panel on the right.

Benchmark

1000 pairs of chests, 3600 ticks, Factorio 2.0.77, yellow tier, 1 stack per transfer:

Per tick it costs about as much as a pair of loaders, but it moves 6.5× more items – far less UPS per item.

License

MIT